The goals of the proposed research are (a) to extend prior work on validating an assessment battery for writing disabilities by investigating the ability of measures in this battery to predict response to treatment; and (b) to validate treatment protocols by showing their effectiveness in preventing or remediating disabilities in specific component writing skills in the primary grades. This research is important because it will help prevent the mental health problems associated with chronic learning problems related to handwriting, spelling, and/or composition, which often arise in early childhood. During each year of this 5-year project, one prevention study in a school setting and one short-term treatment study in a clinic setting will be conducted. A long-term treatment study for children with severe writing disabilities will continue throughout the project. In year 1 the prevention study will compare the effectiveness of components of conventional handwriting instruction and components of handwriting instruction grounded in neurodevelopmental theory. In year 1 the short-term treatment study will compare the effectiveness of grapho- motor responses and computer keyboard responses in learning to spell. In years 2 and 3 both the prevention and short-term treatment studies will compare the effectiveness of teaching spelling based on single orthographic-phonological correspondences (whole written-whole spoken word, letterphoneme, or letter cluster-syllable/rimes) and different combinations of these single approaches. In years 4 and 5 the prevention study will compare the effectiveness of training low-level handwriting and spelling skills, training high-level cognitive processes in writing, or training both low-level and high-level skills on composition growth. In years 4 and 5 the short-term treatment studies will explore the effectiveness of various approaches to teaching planning and revising skills, respectively. Experiments, across years, are designed so that the effects of one-, two-, and three- component treatments can be compared. The goal of the long-term treatment study (years 1 through 5) is to show that severely writing disabled children can be brought up to grade level with intensive, systematic, and individualized theory-based treatment. Results of all studies will be evaluated using state-of-the-art multi- level techniques (at the individual and group level) and growth curve analysis.